Bioequivalence of Cyclosporine A 100 mg Soft Capsules (Cipol-N® vs. Sandimmun Neoral®) in Healthy Korean Volunteers

The bioequivalence of two cyclosporine A (CyA) 100 mg soft capsules (Chong Kun Dang's $Cipol-N^{(R)}$ as the test drug; Korea Novartis' Sandimmun $Neoral^{(R)}$ as the reference drug) was assessed in healthy male Korean volunteers after oral administration of 200 mg CyA according to a randomized crossover design. The whole blood samples were analyzed for the determination of parent CyA in the blood by using a validated HPLC/diode array detector method. The mean $AUC_t$ values for reference and test products were $4095.3{\pm}1397.2$ and $3958.3{\pm}1138.2\;ng{\cdot}hr/mL$, respectively. The mean $C_{max}$ values were $1135.9{\pm}293.2\;ng/mL$ for the reference product, and $985.0{\pm}207.9\;ng/mL$ for the test product. $T_{max}$ was $1.6{\pm}0.4\;hr$ for the reference and $1.8{\pm}0.5\;hr$ for the test product. The differences of $AUC_t$, $C_{max}$ and $T_{max}$ were -3.35, -13.28 and +10.63%, respectively. The point estimates and 90% confidence intervals for $AUC_t$ and $C_{max}$ were 0.981 (0.9171 to 1.0514) and 0.876 (0.8229 to 0.9336), respectively. Based on the pharmacokinetic and statistical data, we conclude that these two products are bioequivalent and can be considered interchangeable in the medical practice.